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Abstract: Neodymium doped YAG transparent ceramics were fabricated by vacuum reactive sintering method using commercial α-Al2O3, Y2O3 and Nd2O3 powders as the starting materials with both tetraethyl orthosilicate (TEOS) and MgO as sintering aids. The morphologies and microstructure of the powders and Nd:YAG transparent ceramics were investigated. Fully dense Nd:YAG ceramics with average grain size of ∼10μm were obtained by vacuum sintering at 1780°C for 8h. No pores and grain-boundary phases were observed. The in-line transmittance of the ceramic was 83.8% at 1064nm. [Copyright &y& Elsevier]

Transparent Er:Lu 2 O 3 ceramics were fabricated by the solid-state reaction method and vacuum sintering followed by hot isostatic pressing. The micrograph of the Er:Lu 2 O 3 transparent ceramics exhibited a pore-free structure with the average grain size of ∼2 μm. The in-line transmittance at 600 nm and 1300 nm were about 80% and 83%, respectively. The absorption, emission spectra and the decay lifetimes of Er:Lu 2 O 3 ceramics were investigated. The 3 at.% Er:Lu 2 O 3 ceramics were pumped by 967 nm InGaAs laser diodes. A maximum output power of 189 mW at 2.7 μm was obtained with a corresponding slope efficiency of 2.16%. [ABSTRACT FROM AUTHOR]

Transparent chromium doped Y 3 Al 5 O 12 ceramics with excellent optical qualities were successfully fabricated by solid state reaction sintering using divalent dopants (CaO and MgO) as sintering aids, and the conversion efficiency of Cr 4+ ion in Cr: YAG ceramic was effectively regulated by various approaches. All samples were fully transparent after vacuum sintered at 1820 °C for 8 h. It was found that under fixed amount of divalent dopants, the conversion efficiency of Cr 4+ ion in Cr: YAG ceramics was significantly increased by increasing Cr doping concentration, elevating annealing temperature, prolonging annealing soaking time or adopting oxygen annealing atmosphere. The absorption coefficient of as fabricated 0.1 at.% Cr: YAG ceramics at 1030 nm reached up to 5.2 cm −1 after annealed at 1300 °C for 30 h under an oxygen atmosphere. It was much higher than that of corresponding single crystal fabricated by traditional Czochralski method. [ABSTRACT FROM AUTHOR]

Solid content of suspension for spray drying was systematically investigated to obtain spherical and dense Nd: granulated particles. The rheological behavior, morphology, size and distribution, apparent and tap densities, and transmittance measurements were used as tools to guide the selection of solid content of suspension. The balanced solid content were 42.0 wt.%. The granulated particles exhibited close to mono-dispersed, spherical and uniform dense aggregates, and mean size was ∼35 μm. Under 60 MPa pressure, the granules were completely crushed without obvious inter-granules void. The homogeneous element distribution and fine microstructure provided high optical quality of Nd:YAG ceramics and the transmittance at 1064 nm reached up to 84.90%. [ABSTRACT FROM AUTHOR]